From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40427) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Yahgl-000601-2N for qemu-devel@nongnu.org; Wed, 25 Mar 2015 05:33:28 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Yahgg-0007pU-KB for qemu-devel@nongnu.org; Wed, 25 Mar 2015 05:33:27 -0400 From: Wen Congyang Date: Wed, 25 Mar 2015 17:36:04 +0800 Message-ID: <1427276174-9130-4-git-send-email-wency@cn.fujitsu.com> In-Reply-To: <1427276174-9130-1-git-send-email-wency@cn.fujitsu.com> References: <1427276174-9130-1-git-send-email-wency@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain Subject: [Qemu-devel] [RFC PATCH COLO v2 03/13] NBD client: connect to nbd server later List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu devel , Fam Zheng , Max Reitz , Paolo Bonzini Cc: Kevin Wolf , qemu block , Lai Jiangshan , Jiang Yunhong , Dong Eddie , "Dr. David Alan Gilbert" , Gonglei , Stefan Hajnoczi , Yang Hongyang , zhanghailiang The secondary qemu starts later than the primary qemu, so we cannot connect to nbd server in bdrv_open(). Signed-off-by: Wen Congyang Signed-off-by: zhanghailiang Signed-off-by: Gonglei --- block/nbd.c | 122 +++++++++++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 108 insertions(+), 14 deletions(-) diff --git a/block/nbd.c b/block/nbd.c index 2176186..3faf865 100644 --- a/block/nbd.c +++ b/block/nbd.c @@ -44,6 +44,8 @@ typedef struct BDRVNBDState { NbdClientSession client; QemuOpts *socket_opts; + char *export; + bool connected; } BDRVNBDState; static int nbd_parse_uri(const char *filename, QDict *options) @@ -254,50 +256,95 @@ static int nbd_establish_connection(BlockDriverState *bs, Error **errp) return sock; } -static int nbd_open(BlockDriverState *bs, QDict *options, int flags, - Error **errp) +static int nbd_connect_server(BlockDriverState *bs, Error **errp) { BDRVNBDState *s = bs->opaque; - char *export = NULL; int result, sock; - Error *local_err = NULL; - - /* Pop the config into our state object. Exit if invalid. */ - nbd_config(s, options, &export, &local_err); - if (local_err) { - error_propagate(errp, local_err); - return -EINVAL; - } /* establish TCP connection, return error if it fails * TODO: Configurable retry-until-timeout behaviour. */ sock = nbd_establish_connection(bs, errp); if (sock < 0) { - g_free(export); + g_free(s->export); return sock; } /* NBD handshake */ - result = nbd_client_init(bs, sock, export, errp); - g_free(export); + result = nbd_client_init(bs, sock, s->export, errp); + g_free(s->export); + s->export = NULL; + if (!result) { + s->connected = true; + } + return result; } +static int nbd_open(BlockDriverState *bs, QDict *options, int flags, + Error **errp) +{ + BDRVNBDState *s = bs->opaque; + Error *local_err = NULL; + + /* Pop the config into our state object. Exit if invalid. */ + nbd_config(s, options, &s->export, &local_err); + if (local_err) { + error_propagate(errp, local_err); + return -EINVAL; + } + + return nbd_connect_server(bs, errp); +} + +static int nbd_open_colo(BlockDriverState *bs, QDict *options, int flags, + Error **errp) +{ + BDRVNBDState *s = bs->opaque; + Error *local_err = NULL; + + /* Pop the config into our state object. Exit if invalid. */ + nbd_config(s, options, &s->export, &local_err); + if (local_err) { + error_propagate(errp, local_err); + return -EINVAL; + } + + return 0; +} + static int nbd_co_readv(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) { + BDRVNBDState *s = bs->opaque; + + if (!s->connected) { + return -EIO; + } + return nbd_client_co_readv(bs, sector_num, nb_sectors, qiov); } static int nbd_co_writev(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) { + BDRVNBDState *s = bs->opaque; + + if (!s->connected) { + return -EIO; + } + return nbd_client_co_writev(bs, sector_num, nb_sectors, qiov); } static int nbd_co_flush(BlockDriverState *bs) { + BDRVNBDState *s = bs->opaque; + + if (!s->connected) { + return -EIO; + } + return nbd_client_co_flush(bs); } @@ -310,6 +357,12 @@ static void nbd_refresh_limits(BlockDriverState *bs, Error **errp) static int nbd_co_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors) { + BDRVNBDState *s = bs->opaque; + + if (!s->connected) { + return -EIO; + } + return nbd_client_co_discard(bs, sector_num, nb_sectors); } @@ -319,23 +372,44 @@ static void nbd_close(BlockDriverState *bs) qemu_opts_del(s->socket_opts); nbd_client_close(bs); + s->connected = false; } static int64_t nbd_getlength(BlockDriverState *bs) { BDRVNBDState *s = bs->opaque; + if (!s->connected) { + /* + * We cannot return -ENOTCONN, otherwise refresh_total_sectors() + * will fail, and we cannot open nbd client. + */ + return 0; + } + return s->client.size; } static void nbd_detach_aio_context(BlockDriverState *bs) { + BDRVNBDState *s = bs->opaque; + + if (!s->connected) { + return; + } + nbd_client_detach_aio_context(bs); } static void nbd_attach_aio_context(BlockDriverState *bs, AioContext *new_context) { + BDRVNBDState *s = bs->opaque; + + if (!s->connected) { + return; + } + nbd_client_attach_aio_context(bs, new_context); } @@ -438,11 +512,31 @@ static BlockDriver bdrv_nbd_unix = { .bdrv_refresh_filename = nbd_refresh_filename, }; +static BlockDriver bdrv_nbd_colo = { + .format_name = "nbd+colo", + .protocol_name = "nbd+colo", + .instance_size = sizeof(BDRVNBDState), + .bdrv_parse_filename = nbd_parse_filename, + .bdrv_file_open = nbd_open_colo, + .bdrv_co_readv = nbd_co_readv, + .bdrv_co_writev = nbd_co_writev, + .bdrv_close = nbd_close, + .bdrv_co_flush_to_os = nbd_co_flush, + .bdrv_co_discard = nbd_co_discard, + .bdrv_getlength = nbd_getlength, + .bdrv_detach_aio_context = nbd_detach_aio_context, + .bdrv_attach_aio_context = nbd_attach_aio_context, + .bdrv_refresh_filename = nbd_refresh_filename, + + .has_variable_length = true, +}; + static void bdrv_nbd_init(void) { bdrv_register(&bdrv_nbd); bdrv_register(&bdrv_nbd_tcp); bdrv_register(&bdrv_nbd_unix); + bdrv_register(&bdrv_nbd_colo); } block_init(bdrv_nbd_init); -- 2.1.0